Generation of three-dimensional objects

ABSTRACT

According to one example, there is provided a system for managing the generation of three-dimension objects by an additive manufacturing system. The system comprises a processor to receive one or multiple virtual objects, to generate a spatial arrangement of those objects within a virtual build volume, to control an additive manufacturing system to process the virtual build volume, to modify the virtual build volume in response to a request, and to control the additive manufacturing system to process the modified virtual build volume.

RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. § 371 of PCT application number PCT/US2014/056789, having an international filing date of Sep. 22, 2014, which claims priority to PCT Application No. PCT/US2014/053405filed on Aug. 29, 2014, entitled “MODIFYING DATA REPRESENTING THREE-DIMENSIONAL OBJECTS”the disclosures of which are hereby incorporated by reference in their entireties.

BACKGROUND

Many different types of additive manufacturing techniques for generating three-dimensional objects on a layer-by-layer basis are known. Many of these techniques, however, are generally slow, and it may take a considerable time to generate even a small object.

BRIEF DESCRIPTION

Examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a system 100 according to an example;

FIG. 2 is block diagram of a build volume manager according to one example;

FIG. 3 is a flow diagram outlining a method according to one example;

FIG. 4 is an illustration of a build volume according to one example;

FIG. 5 is an illustration of a virtual object according to one example;

FIG. 6 is an illustration of a virtual build volume according to one example; and

FIG. 7 is an illustration of a time line according to one example.

DETAILED DESCRIPTION

Some additive manufacturing techniques generate three-dimensional objects within a volume of a build material (hereinafter referred to as a build volume). For example, some techniques form successive layers of a build material, such as a powdered or liquid build material, on a support platform, and then selectively solidify portions of each layer of build material, before forming a subsequent layer of build material. Additive manufacturing systems that generate three-dimensional objects in this manner may include, for example, selective laser sintering (SLS) systems, stereo lithography (SLA) systems, and powder-based three-dimensional printing systems.

To generate three-dimensional objects, one or multiple virtual objects may be spatially arranged within a virtual build volume. A virtual object may be, for example, a digital model of an object that is to be generated by an additive manufacturing system.

The virtual build volume corresponds to a build volume of a given additive manufacturing system within which objects may be generated.

An additive manufacturing system processes successive layers of build material corresponding to respective slices of the virtual build volume to generate objects within the build volume. The processing may include, for example, selectively solidifying portions of each layer of build material in accordance with object cross-sections that may be present in corresponding slices of the virtual build volume.

Since such systems generate objects within a build volume, generated objects may be removed from the build volume once all of the objects within the build volume have been generated.

The processing of a given build volume may take many hours, depending, for example, on the type of additive manufacturing system used and the size of the build volume. Accordingly, once an additive manufacturing system has started to process a build volume the additive manufacturing system is effectively busy until the whole build volume has been processed, or unless the build process is cancelled. However, cancelling processing of a build volume may result in a significant loss of time, and any objects not fully generated within the build volume will be incomplete. Furthermore, cancelling the processing of a whole build volume may result in significant loss of build material.

Referring now to FIG. 1, there is shown a schematic view of a system 100 according to an example. The system 100 comprises a build volume manager 102 for managing an arrangement of objects within a build volume 112 to be generated by an additive manufacturing system 104. In one example, the build volume manager 102 may generate control signals or data 103 that may be used to control, either directly or indirectly, the additive manufacturing system 104.

In one example, as shown in FIG. 2, the build volume manager 102 comprises a processor 202, such as a microprocessor or microcontroller, coupled to a non-transitory computer readable memory 204, for example through a communications bus (not shown). The memory 204 stores build volume management instructions 206 which are machine readable instructions that, when executed by the processor 202, cause the build volume manager 102 to manage a build volume of an additive manufacturing system as described herein in various examples.

Operation of the system 100 will now be described with additional reference to the flow diagram of FIG. 3.

At 302, the build volume manager 102 generates a virtual build volume 108. The virtual build volume 108 includes a spatial arrangement of one or multiple virtual three-dimensional objects, such as virtual objects 106 a and 106 b, to be generated within the build volume 112 by the additive manufacturing system 104. In one example the build volume manager 102 generates data representing a spatial arrangement of a virtual build volume from data representing one or multiple three-dimensional objects.

Each virtual object may be, for example, defined in any suitable data format, such as a vector data format. Each virtual three-dimensional object may be generated, for example, from a suitable computer-aided design (CAD) application, from a three-dimensional scanner, or from any suitable source.

In one example, the build volume manager 102 may be implemented as a software driver, or other software application, that a user uses to send a three-dimensional print job defining one or multiple objects to be generated by an additive manufacturing system.

In one example, the build volume manager may obtain multiple virtual objects, such as objects 106 a and 106 b, that are to be generated by the additive manufacturing system 104. The build volume manager 102 may determine a spatial arrangement of one or more of the obtained virtual objects within the virtual build volume 108, based on various criteria. The spatial arrangement may include the orientation and position of each object within the virtual build volume 108. Such criteria may include, without limitation: an object build deadline; an object priority; object interdependencies; structural characteristics required for a particular orientation of a part; acceptable geometrical error tolerance for a particular orientation of a part; spatial arrangement of objects to facilitate a post-processing operation, and volumetric optimization of the build volume.

In one example the build volume manager 102 may determine a spatial arrangement by determining a volumetric optimization of the virtual build volume 108. For example, the build volume manager 102 may perform one or multiple geometric operations, such as rotations, translations, etc. of objects to obtain an efficient spatial arrangement, whilst respecting appropriate criteria such as, without limitation: minimal object to object spacing; appropriate thermal spacing (depending on the additive manufacturing techniques employed); and desired strength axes. The build volume manager 102 may use, for example, finite element analysis (FEA) to assist the determination of the orientation of a part, for example to meet a desired object strength characteristic.

In one example the build volume manager 102 determines when to control the additive manufacturing system 104 to start processing the virtual build volume 108 to generate the build volume 112. In another example a user may determine when the build volume manager 102 is to start processing the virtual build volume 108 to generate the build volume 112.

At block 304, the build volume manager 102 controls the additive manufacturing system 104 to begin generating the virtual objects 106 a and 106 b within the virtual build volume 108. In one example, the additive manufacturing system 104 processes successive layers of a build material corresponding to slices of the virtual build volume 108.

In one example, the build volume manager 102 processes the virtual build volume 108 and sends corresponding control data 103 to the additive manufacturing system 104.

In one example, the build volume manager 102 may generate and send data representing individual slices 110 a to 110 n of the virtual build volume 108, where each slice corresponds to a layer 114 a to 114 n of build material to be processed by the additive manufacturing system 104 within the build volume 112. In one example each slice 110 a to 110 n corresponds to a single layer of build material 114 a to 114 n. In other examples, multiple slices may correspond to a single layer of build material.

In one example, the build volume manager 102 may generate and send data to the additive manufacturing system 104 that represents all of the slices 110 a to 110 n of the virtual build volume 108. In another example, the build volume manager 102 may generate and send data that represents a single slice of the virtual build volume 108, and may send data that represents a subsequent slice of the virtual build volume 108 when requested by the additive manufacturing system 102.

In one example the control data 103 may be adapted by the build volume manager 102 based on characteristics of the additive manufacturing system 104.

At block 306, the build volume manager 102 waits to receive, or otherwise obtains, a request to modify the virtual build volume 108. If such a request is received, for example through a suitable input to the build volume manager 102, at block 308 the build volume manage 102 determines if the request can be fulfilled.

A request to modify the virtual build volume 108 may take different forms, and may include, without limitation, one or more of: a request to cancel the generation of an object; a request to add a new object; a request to displace an object; a request to substitute one object for another object; a request to duplicate an object; and a request to modify a characteristic, such as a color characteristic, or object property characteristic, such as a strength characteristic, a smoothness characteristic, or the like.

The determination by the build volume manager 102 as to whether a request to modify the virtual build volume 108 may be fulfilled may depend on the type of request, and may also depend on the number of layers of the build volume 112 that have already been processed by the additive manufacturing system 104.

For example, to fulfill a request to add a new object into the virtual build volume 108 the build volume manager 102 has to determine whether there is sufficient space in the un-processed portion of the build volume 112 to accommodate the new object. For example, to fulfill a request to cancel the generation of an object in the build volume 112, to move an object, or to modify a characteristic of an object, the build volume manager 102 has to determine whether the object has already been generated, or at least partially generated, within the build volume 112.

In one example, the build volume manager 102 determines from the additive manufacturing system 104, the layer of the build volume 112 that is currently being processed. This enables the build volume manager 102 to determine the number of layers that have been processed by the additive manufacturing system 104. In other examples, however, the build volume manager 102 may obtain from the additive manufacturing system 104 a layer other than the current layer, for example the last complete layer that was processed, the next layer to be processed, or any other suitable layer. The layer may also be referred to as the z-count, as it represents the offset in the z-axis of the current layer of build material being processed.

By knowing the number of layers of the build volume 112 that have been processed by the additive manufacturing system 104 enables the build volume manager 102 to determine whether a request can be fulfilled.

FIG. 4 illustrates a build volume 112 of which a portion 402 thereof, comprising layers of build material 116 a to 116 e, has been processed by the additive manufacturing system 104. It can be seen that a portion of the object 406, corresponding to the virtual object 106 a has been generated within the build volume 112, whereas no object corresponding to the virtual object 106 b has yet been generated. It can also be seen that a portion 404 of the build volume 112 remains un-processed.

Accordingly, if the request is to modify the object 406, the request cannot be fulfilled. However, if the request is to cancel the generation of the virtual object 106 b, this request can be fulfilled. Similarly, by knowing the height of each layer and the maximum height of the build volume 112, or by knowing the number of layers of build material within the build volume 112 the build volume manager 102 is able to determine the amount of available space in the build volume 112 within which modifications to the spatial of arrangement of objects may be made.

For example, a request may be received to cancel the generation of virtual object 106 b, and to generate a new object 502 shown in FIG. 5.

The build volume manager 102 determines (block 308) that the virtual object 106 b has not yet been generated or partially generated and so may fulfill the request to cancel its generation by suitably modifying (block 312) the virtual build volume 108. The build volume manager 102 also determines (block 308) that the new virtual object 502 may be generated in the un-processed portion 404 of the build volume 112, and so modifies (block 312) the virtual build volume 108 that corresponds to the portion 404 of the build volume 112, as shown in FIG. 6. Since the virtual object 106 a has only been partially generated in the build volume no modifications are made thereto in the virtual build volume 108.

As previously mentioned, the build volume manager 102 may perform one or multiple geometric operations on the new virtual object 502, or any on other virtual objects which have not yet been processed, such as rotations, translations, etc. of objects to obtain an efficient spatial arrangement, whilst respecting any appropriate criteria, such as those criteria previously mentioned, to determine whether the request may be fulfilled. For example, the build volume manager 102 may attempt to determine a new spatial arrangement of objects within the virtual build volume 108 that would allow the new virtual object to be included therein. Any objects which have been partially processed, such as the object 106 a, may not be able to be modified, other than for to cancel the generation of the object.

At block 304 the build volume manager 102 controls the additive manufacturing system 104 to process the modified virtual build volume 108, for example by sending suitable data or control signals thereto.

In one example, the build volume manager 102 instructs the additive manufacturing system 104 to disregard any previously received control data and instructs the additive manufacturing system 104 to process new data representing the un-processed portion 604 of the virtual build volume 108.

In one example, the build volume manager 102 may send data to the additive manufacturing system 104 that represents all of the slices corresponding to the un-processed portion 604 of the virtual build volume 108.

In another example, the build volume manager 102 may send data that represents a single slice of the virtual build volume 108, and may send data that represents a subsequent slice of the virtual build volume 108 when requested by the additive manufacturing system 102.

In a yet further example, the build volume manager 102 may send data that represents slices of just the object, for example along with an offset within the build volume.

Some additive manufacturing techniques, such as selective laser sintering and powder-based three-dimensional printing system, may be sensitive to delays introduced between the processing of successive layers of build material. For example, inter-layer object strength may be related to the temperature at which layers of build material, or different portions of layers of build material are maintained. Accordingly, in one example the build volume manager 102 does not interrupt the processing of layers of the build volume 112 by the additive manufacturing system 104 until it has determined whether the request to modify to the build volume 112 can be fulfilled and has subsequently generated the new control data or signals to control the additive manufacturing system 104.

If the time it takes to process the request is greater than the time it takes the additive manufacturing system 104 to process a layer of build material in the build volume 112, then any layers of build material processed whilst the build volume manager 102 is processing the request may be need to be taken into account. This may be the case, for example, if the request relates to adding a new object or modifying the spatial arrangement of objects within the build volume.

The build volume manager 102 may be used, according to one example, as a dynamic object queue manager for an additive manufacturing system.

An example scenario is described below with additional reference to FIG. 7.

At time t0 the build volume manager 102 receives a request to build a virtual object 702 and a virtual object 704. The virtual object 702 has data associated with it that indicates that it is required for time rt1, and the virtual object 704 has data associated with it that indicates that it is required for time rt3.

At time t1 the build volume manager 102 generates a virtual build volume 706 that includes the virtual objects 702 and 704 and at time t2 sends data representing at least a portion of the virtual build volume 706 to the additive manufacturing system 104. At time t3, the additive manufacturing system 104 starts processing the build volume.

At time t4 the build volume manager 102 receives a request to build a yet further object 708. The virtual object 702 has data associated with it that indicates that it is required for time rt2.

The build volume manager 102 determines that the request may be fulfilled by removing the virtual object 704 from the virtual build volume 706, and adding the object 708 to the virtual build volume 706.

At time t5 the build volume manager 102 modifies the portion of the virtual build volume which has not yet been processed by the additive manufacturing system 104, to generate a modified virtual build volume 710.

At time t6 the build volume manager 102 sends data representing at least a portion of the modified virtual build volume 710 to the additive manufacturing system 104.

At time t7 the additive manufacturing system 104 completes processing of the build volume, and hence the generated objects corresponding to the virtual objects 702 and 708 may be removed from the processed build volume.

At time t8 the build volume manager 102 may generate a new virtual build volume containing the virtual object 704, such that it may be generated by the additive manufacturing system 104 by its required time rt3.

It will be apparent that the build volume manager as described herein may be used in numerous manners, and may be particularly useful in managing the generation of objects in a dynamic manner by an additive manufacturing systems. This may be particularly convenient as it enables a build volume being processed by an additive manufacturing system to be modified, in substantially real-time, without having to wait for the entire build volume to be processed.

In the example shown the build volume manager 102 is separate from the additive manufacturing system 104. In one example, the build volume manager 102 may be an application running on a locally or remotely connected processing device, such as a computer server.

In another example, the build volume manager 102 may be integrated with the additive manufacturing system 104.

It will be appreciated that examples described herein can be realized in the form of hardware, software or a combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape. It will be appreciated that the storage devices and storage media are examples of machine-readable storage that are suitable for storing a program or programs that, when executed, implement examples described herein. Accordingly, some examples provide a program comprising code for implementing a system or method as described herein and a machine readable storage storing such a program.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 

The invention claimed is:
 1. A method of managing generation of three-dimensional objects by an additive manufacturing system, comprising: generating, a spatial arrangement of virtual objects within a virtual build volume, wherein the virtual build volume corresponds to a build volume of the additive manufacturing system; controlling the additive manufacturing system to process successive layers of a build material corresponding to the virtual build volume; receiving a request to modify the virtual build volume; determining a number of layers of build material that have been processed by the additive manufacturing system when the request to modify the virtual build volume is received; determining from the determined number of layers, a portion of the virtual build volume not yet processed by the additive manufacturing system; determining whether to accept the request based on the determined portion of the virtual build volume that has not yet been processed by the additive manufacturing system; based on a determination that the request is to be accepted, modifying the virtual build volume to accommodate the request; and controlling the additive manufacturing system to continue processing layers of the build material based on the modified virtual build volume.
 2. The method of claim 1, wherein receiving a request comprises receiving one or more of: a request to cancel the generation of an object; a request to add a new object; a request to displace an object; a request to substitute one object for another object; a request to duplicate an object; and a request to modify an object characteristic.
 3. The method of claim 1, wherein the received request is a request to add a new object, and wherein determining whether to accept the request further comprises determining whether there is sufficient space in the portion of the build volume that has not yet been processed to accommodate the new object.
 4. The method of claim 1, where the received request is a request to move or cancel an object, and wherein determining whether to accept the request further comprises determining whether a portion of the object has already been generated by the additive manufacturing system.
 5. The method of claim 1, wherein determining whether to accept the request further comprises determining whether to accept the request based on data associated with an object of the virtual objects.
 6. The method of claim 1, wherein determining whether to accept the request further comprises determining whether to accept the request based on performing one or multiple geometric operations on a new virtual object or any other virtual object in the virtual build volume to determine a new spatial arrangement of virtual objects within the virtual build volume that results in the new virtual object being included in the modified virtual build volume.
 7. The method of claim 1, wherein controlling the additive manufacturing system comprises generating and sending data representing slices of the virtual build volume to the additive manufacturing system, and further wherein, based on a determination that the request is to be accepted, modifying the virtual build volume in accordance with the request, and generating and sending modified data representing slices of the modified virtual build volume to the additive manufacturing system.
 8. The method of claim 7, further comprising sending the modified data to the additive manufacturing system without interrupting processing of a layer of build material.
 9. A system for managing the generation of three-dimensional objects, comprising a processor to: obtain one or multiple virtual objects; generate a spatial arrangement of the obtained one or multiple objects within a virtual build volume; control an additive manufacturing system to process the virtual build volume, wherein the virtual build volume corresponds to a build volume of the additive manufacturing system; receive a request to modify the virtual build volume; determine a number of layers of build material that have been processed by the additive manufacturing system when the request to modify the virtual build volume is received; determine from the determined number of layers, a portion of the virtual build volume not yet processed by the additive manufacturing system; determine whether to accept the request based on the determined portion of the virtual build volume that has not yet been processed by the additive manufacturing system; based on a determination that the request is to be accepted, modify the virtual build volume according to the request; and control the additive manufacturing system to process the modified virtual build volume.
 10. The system of claim 9, wherein the processor is to receive one or more of: a request to cancel the generation of an object; a request to add a new object; a request to displace an object; a request to substitute one object for another object; a request to duplicate an object; and a request to modify an object characteristic.
 11. The system of claim 9, wherein the processor is to generate and send data representing slices of the virtual build volume to the additive manufacturing system, and wherein, based on a determination that the request is to be accepted, the processor is to modify the virtual build volume in accordance with the request, and to generate and send modified data representing slices of the modified virtual build volume to the additive manufacturing system.
 12. A non-transitory computer readable medium on which is stored processor understandable instructions that, when executed by a processor cause the processor to: generate an arrangement of virtual objects within a virtual build volume; control an additive manufacturing system to process successive slices of the virtual build volume, wherein the virtual build volume corresponds to a build volume of the additive manufacturing system; receive a request to modify the virtual build volume; determine a number of layers of build material that have been processed by the additive manufacturing system when the request to modify the virtual build volume is received; determine from the determined number of layers, a portion of the virtual build volume not yet processed by the additive manufacturing system; determine whether to accept the request based on the determined portion of the virtual build volume that has not yet been processed by the additive manufacturing system; based on a determination that the request is to be accepted, modify the virtual build volume according to the request; and control the additive manufacturing system to process successive slices of the modified virtual build volume. 